Mozilla Firefox 26 is now available for Windows, Mac, Linux, and Android.
Firefox now blocks all Java plugins by default by implementing 'Click to Play' functionality for improving security and stability of the browser.
Firefox's memory consumption has been reduced significantly. Firefox now decodes (decompress) images that are visible, rather than every image on the page. For image-heavy pages, this results in a huge reduction in memory footprint (as seen in the graph below).
In the Android version, the startup screen has been redesigned. The new UI gives users quick and easy access to their browsing data, including top sites, history, bookmarks, Reading List, and search.
Other New Features
Firefox 26 allows H.264 encoded video to be played on a Linux system if the appropriate GStreamer plug-ins are installed and adds support for MP3 audio decoding on Windows XP. Read the release notes here.